Conventional varifocal objectives of this type can be fitted with various attachments to extend their ratio of maximum and minimum overall focal lengths, either beyond the wide-angle end or beyond the telephoto end of their normal operating range. Such an extension of the normal range can also be effected by an exchange or an interposition of lens members, e.g. with the aid of a revolving carrier or turret. These attachments are, generally, somewhat unhandy, especially when it is desired to shift the operating range toward the shorter focal lengths since the resulting increase in the object-side field angle requires lenses of larger diameter at the front of the objective. Thus, a conventional wide-angle attachment includes a large negative front lens followed by several lenses or lens combinations air-spaced therefrom. The effect of such an attachment is to multiply the numerical values of the overall focal length in the various positions of the shiftable components by a factor smaller than unity, with the law of relative displacement of these components remaining unchanged; on the telephoto side the multiplication factor has a value greater than unity.